The present invention relates to a sucking and filtering vehicle for dust and trash collecting, such as a sweeper machine for industrial and commercial areas or street surfaces.
It is known that suction means arranged in sweeper vehicles or machines of the above type act in synergy with other members such as brushes and rollers acting on the ground and have the task of moving a large mass of air.
This air drawn in by the suction means is necessarily filtered before being discharged to the surrounding atmosphere.
Filtering takes place by means of members that must comply with at least two requirements: they must define wide filtering surfaces and be adapted to be efficiently recleaned, also while the vehicle is moving, in order to avoid work being stopped due to clogging of the filtering surfaces.
In order to meet the first requirement, a so-called "pocket" filter is used, which is made of an acrylic fabric as large as many square meters which is disposed in a folded configuration so as to form several loops or pockets. These loops or pockets are disposed in side by side relation, to define overall dimensions consistent with the sweeper machine sizes, and are maintained in place by appropriate tie-rods.
For meeting the second requirement, the filter is positioned in the same container or tank in which building up of dust and trash takes place and, in addition, at least one shaker member is provided close to the filter, said shaker being capable of shaking the filter to cause dust stored on the filtering surfaces to fall into the tank itself. Practically, within the tank the filter is placed below a sucking pipe passing through the tank cover for example, and above said shaker member.
This technical solution taken as a whole has the quality of making available large filtering surfaces gathered to form a relatively reduced volume, and to remedy clogging which is a drawback of filtering surfaces, making dust stored on said surfaces fall into the tank.
There are however several drawbacks.
A first drawback can be identified by the fact that sweeper vehicles or machines of the above specified structure are limited in terms of available construction solutions, as it is always necessary that the air suction ducts should terminate on top of the tank, above the filtering means, in turn hanging from the upper portion of the tank.
Another drawback resides in that filtering surfaces are not utilized at best, because suction is always carried out in a single direction, in particular the direction facing the tank top, so that some areas of the filtering units are more engaged and utilized than others.
Another drawback of great importance is represented by the fact that the filtering surfaces tend to get continuously clogged, because they are located within the tank or trash container, where due to the continuous introduction of material, turbulence and presence of dust are very high. So it may happen that also particles of dust of great sizes that should be intended for laying on the tank bottom, due to said turbulence may accidentally rest on the filtering surfaces.
The continuous clogging of the filtering surfaces causes a more reduced filter efficiency, even in the presence of a frequent activation of said shaker member.